Field of the Invention
The present invention relates to a data management system and a data management method using a key-value type database.
Priority is claimed on Japanese Patent Application No. 2015-103744, filed May 21, 2015, the contents of which are incorporated herein by reference.
Description of Related Art
All patents, patent applications, patent publications, scientific articles, and the like, which will hereinafter be cited or identified in the present application, will hereby be incorporated by reference in their entirety in order to describe more fully the state of the art to which the present invention pertains.
Generally, when measured data is managed, the data is accumulated in a relational database (RDB) for collecting the data from a sensor using a setting terminal or the like directly connected to a measurement device such as a sensor (for example, see Japanese Unexamined Patent Application, First Publication No. 2011-221799).
In particular, thousands of measurement devices are attached to various parts of a facility such as a plant. The measurement devices continuously transmit measurement results in units of seconds via the above-described setting terminal. Thus, an amount of data accumulated in plant management is considered to be significantly large. There is a demand for connecting the setting terminal to the measurement device in the plant and performing data measurement while checking the part to which the measurement device is attached. Thus, when the measured data is accumulated, the setting terminal is frequently connected to a network of the data management system and a disconnection operation is performed after the data is accumulated.
Also, a key-value database which has recently attracted attention is an example of a not only SQL (NoSQL) database, and has a more flexible data structure than the RDB. The data structure of the key-value database is directed to the distribution of a store (storage) and considered to outperform a general RDB in availability and reading performance for a large amount of data (for example, see Japanese Unexamined Patent Application, First Publication No. 2014-211790).
On the other hand, it is desirable that a connection to or a disconnection from a network of a data management system using an NoSQL database operate to be enabled in any node in data management of the plant as described above. This node represents a server, a personal computer (hereinafter referred to simply as PC), and a setting terminal (for example, a portable terminal such as a tablet terminal) in the data management system.
However, the above-described key-value type database is a distribution type database for distributing and storing data through terminals to accumulate a large volume of data and the data is accumulated in storage media of a plurality of nodes.
Therefore, there is a problem in that the node connected to the network is not effectively utilized as a storage medium for storing a large volume of data because no data is accumulated in a newly connected node or because a detached node is not used for accumulating data either when the node optionally operates to be connectable to a network or detachable from the network.